A problem while working with 2D graphics, in the style of big concept maps or other kind of diagrams, is that when the matter is complex, they can become a problem to navigate and edit them like in the next very cluttered map:

This is unavoidable if you need to show (or print) the map as single unit.

However, with the help of software, you can divide the map in hierarchically contained sub-maps, spanning multiple levels. Consider the next diagram, made with ThinkComposer, representing a simple aircraft design as an advanced concept map:

With this multilevel capability you can “compose” (or decompose) your ideas to any extent into a single document. Plus, notice that you can still connect nodes, not within the same view (map/diagram), by using Shortcuts that you can point/click to easily navigate to the original source.